Method of building dams.



specification.

40 nent work .shrill be .stopped or seriously intl-i ii-rcd wit h UNITED STATEs WILLIAM L. CHURCH, OF

EWTON MASSACHUSETTS.

METHOD OF BUILDING DAMS.

Specification of Letters Patent.

Patented Nov. 12,1907.

Application filed .I nly 25. 1907. Berixl Se. 385.448-

, To all whom il may concern:

Ile it known than, l. \\'n.l.r.\.\i L. ('nizucn, of Newton. .in ilu pounly of Middlesex :1nd Stute of Massachusetts, lm\eiu\"f-|i 1e|l certain lll-wund useful Improvements in 5 Methods-of Building Dum. o which the following is u This invention relate.` particularly to what :u'e known no hollow reinforced concrete dams. which :ire constructed by forming concreti with suitable reinforcing l material in the locution to be occupied bv the dani,

suitable moldsl or forms beine employed.

Under the orflinur" im tlxods oi constructing flume. ol solid masonry, n ne. @muy procedure is to unwnter sa);

. one h-.ili of the rivlr bed ul r1. time by mmins oi :i eoffer l dum from which the-water is pumped ont. As this coffer dem is necessarily pentium-nl. throughout the Whole work oi construction. it. must be mnd:- hign enough and strong enough to withstand ull expected floods occurring durincr u relativi-Lx' long period of construction. 'The Potier dum is therefore expensive :md the time of building il necessarily consumes` the most ndvnntngeous period of the your for construction; namely` the period oi extreme low water. The expense of vofferflmu beim,r :vieri-ut, the tendency is to minimize thee-'istanti tukeclmnceson ihelimds. insu "result i't happens in n large proportion of euses that floods of unexpected'severity occur during the progress -of the work, over-topping :ind damaging the coffer hun and necessarily suspending work on the muin construc- 0 tion und often involvine e. great-dead of diunuge lo the latter.

The object of my invention is, first. to minimize thtl primo costmf the eoffer dum by making its uegippljv only to the initial stages oi the permanent coatruclion;

second, tu shorten the time lost in the eonstructionoi the coffer darn, thereby enabling the pernnulent work to be undertaken und vpnn-u d during the most favomhle season, und third. to make it snbsluntiulbv ilnlmssihle that-oven if alloorl .should oei-ln'. lli'A permall Y l or any.resuluuu dumzige involved. The general effect of my invention therefore is lo pre-illy lisser lberisks attendant upon hydraulic work, und greatly expedite the time olits complet ion, :ill of which tend to u mote- 4,5 rial reduction in cost.

'l ln cnrryingout my inw miou, l proceed tirs! lo build it iight temlmmry colcr dam so as 4o umwuerfmmpori tion of the river bed, bulsuid cutter-dum, beine intended uulyoproteet the permane-ul work for u short time in l u itsinitinl surges, is mudo very light und inexpensive se l if accidentally' ovcrtopped no considerable.- oiztlny 'Urt repair is involved. Ou n certain class ol' ioumlu' 2 lions al coller dum muy he dispensed with Altogether und l proceed to build the footing, course of the future buttresses up to a certain height, as, for instance, three eet above the ordinary level of the water, which footing coursei may, for convenience, call a pier. Ido not build ihe dam above this Stage at all until these piers :ire all in position across the entire width of the river. The building of these piers involves relatively a very snnll amount of labor, as they are simple in form and wntain but a'small amount o concrete. 65 This part. =i the Work can therefore be pushed quickly to completion, und when completed the Colfer dam muy be :it once removed or uilowc'lto float away without cha'nm of futur-'e d-.unzige to the worl'.. Assuming :but the eor't'er dam has been removed or carried away, 70

l then have :i series of isolated pier bases arranged like stepping stones across the whole river, forming the busevsectii'ms of the future buttresses, or the said bases may be termed the skeleton buse of the dam. The subsequent work oi building the upper works er the mnjorpor'tion of the (hun, including the main portion o thev deck, the crest und the apron, above this line can therefore be carried on hy temporary scaffolding luid on the piers und nt the same time be entireiy free from dinger oi thiods. -The water of the river runs through between the piers ut all ordinary stages without interrupting the work going on above it., said piers being sepzimtml by unobstructed witter courses. The entire width of the river is obstructed only in the retin whit-inthe thickness of the piers` bears to the distances between writers of piers. llveu .tn excessive Hood will mus@- no greater luirni thun to tempomrily suspend operslious, but n. lood which would rise to great heights when compressed into one half o i the river by the onin-.iry coller dam method, will rise to only a very lmocbrwte height when allowed to llow freely between uII the piers without sensible interruption. Hoving completed the dam above the skeleton base with thewnter still flowing through underneath the y upper works, I select a favorable time of low water, und closel the successive openings one after another un-` til the riveris compressed into :is few openings as will mko eure of it when ruiming, say, one half full. These [iual openings are then simultaneously closed in any suitable way. 1 prefer in closing the said openings 100 to succeively add extensions to the completed portion of the deck, the said extensions being carried dowuwunlly betwwn the pier buses. 1 prefer tu employ, in'elosing the openings between the pier buses, the method und comtruction represeutml in Letters lC Patent of the United States, No. 781,871, dated Fel mary 7, i905, although the invention is not dependent upon the-methml adopted for closing the dam, either as to its suecsive openings or the iinal closing, butl l an individual caisson substituted. on for 1u-h pier. g relates solely to the method oi constructing the dam 110 fi ving onwetend some portion of the river or the without'dmger of interruption of the operation from` .'en i li e( :mingle pier by either d the above meth-:digi

Of the accompanying drawings forming a part oi this fper:ificntion,-Figure l represents n perspective View illustrating my improved method of building s. rouerete dam. Fig. 2 represents n section 'm inw 2--2 of Fig. 1. Fig. 3 represents n. view similar to Fig. 2, showing'the deck of the dam extended downwardly to close. the openings between the pier luist-s represented in Fig. 2.

Referring to the drawings, a a represent the pier bases, whieh are built. independently of meh other on the bod or'. the stream or on nu especially prepared foundation. the said pier he" es being erected toopoint above the ordinary level of the water, and constituting E a skeleton base, between the members of which flu l water of the stream is adapted to flow freely b represents the deck of the dum, c represents the crest, :md represents the apron, these parts being of reinforced eonercte, and collectively forming a hollow shell.

'l'hc deck, crest und apron are preferably supported by extensions a of the piers, said extensions being huilt upon the piers, and having their edges formed to correslwnd to thecontonr of the inner sides of the deck, crest and apron. The declr,-as first constructed, extends from the upper portions of the pier bases to the crest, the lower portion of the deck, as thus constru'ctf ed, being extended outwardlyto iorm a horizontal ledge or shelf b, in which are openings b'l coinriding with the spaces or water courses between the pier bases. the ends of said openings registering with vertical grooves b fo'rmed in the aides of the pier bases. After the completion oi the upper works formed by the pier extensions a', the dock, the crest, and the prom-the wal ter oursfes between tho pier brises and the upperi works are closed suevessively by luxilding downwardlyoxtending decl; extensions h of reinforo-d Concrete,

` said extensionsengngiugtheopeningsband thegrooves I lr", and lieing built between temporary forms applied in the manner ser forth iu said Letters Patgit. No.

SLTl

As above ndifnt -d,"my invention is not limited to the constrm-tion und modr` oi operation here illustrated andV described for rios-ing the openings lit-tween tlm pier bases and below the upper Works, and the sueessive closure of said openings may be accomplished in any other lnimble n'ay und h v :my olhvr suitable mt'llni l claimzl 1. The method herelnhefore described or building n dnm. the sunnrousisrin; in building u skeleton hns vomposed ol' :l series oi' irmlnted piers sepurntv-d by unobstructed water vourses. then buildin; un A nid skeleton hase uhove the smid u'nit-r r-onrsvs, the upper works of tludum, und than vompieting the inw@ hy suevessh-riy closing the spun-s between the pvrs below tinl upper works. v

'i'he method hervnbefore described or huiidlm: n dam. the sume consistingr in building u skeleton imsu t-olnposvd of :l series of isolntvd piers extending erossn'w ol' the dum. and 1 pn rxted lo unohstrmtmi watt-r mul-ws. then a-xtr-nrL Im.: said piers upwnl'diy to form butin-ssen. tinn building the upper portion o. the deuk :1nd the erest of ihr mm on sn'id piers and hntnesses. leaving the water vonrses unobstrwted, :1nd thon complotto: the hose by slu'cessively adding.: extensions to tinder'k, snid extensions rlmingthe spaces between the pit-rs.

' In testimony whereof l have :|ll\'e|l my signature. in

prem-nmo two wiwi-swt. 

